You may have scenarios where a contact will need to be associated with more than one account (they fly with their company but also personally). If the contact details are the same between the two accounts, you can associate the one contact record with both. This will make it easy to update information since you can change it for the one contact record and it will display in both.
From the contact detail page click the Accounts tab
Select the additional account you want to associate the contact to and click Link
A green confirmation message will appear, indicating that the Link was completed successfully. You will now see the linked company listed in the Account Grid. Need to remove the Account from that Contact? Simply click on Delete and the Link will be removed.
Ref: C-A02